In the Add Class screen, when you choose the manual, the drop-down showing the manual is wide enough to read the names of the manuals. However, when the control is not dropped down, the name of the selected manual is cut off.

It looks like the page layout was done to be visually pleasing, with all the drop-downs on the page being the same width. However, I suggest that the Manual and Lesson Material drop-down be made wider so you can more easily read the selected manual's name.